Three Part Question

Clinical Scenario

A 3-year-old girl is brought to the emergency department by her parents. She has vomited multiple times and has been feverish and lethargic over the last 24 h. On examination, she is feverish, she has a stiff neck and Kernig's sign is positive. You are concerned about the possibility of meningitis but do not want to put a child through an unnecessary lumbar puncture. You wonder how accurate the above signs of meningeal irritation are in detecting bacterial meningitis in children.

108 children aged 2 months to 16 years with clinically suspected meningitis

Meningitis defined as >6WBC/mcl microliter of CSF

Prospective cohort study

Nuchal rigidity

Sensitivity 65% (95% CI 50% to 77%)

PPV 0.8

Small sample size

28% of patients lacked documentation about presence or absence of eningeal signs

Kernig's sign

Sensitivity, 27% (95% CI 15% to 41%)

Specificity, 87% (95% CI 68% to 96%)

PPV 0.77

Brudzinski's sign

Sensitivity, 51% (95% CI 36% to 65%)

Specificity 80% (95% CI, 63 to 92)

PPV 0.81

Comment(s)

Bacterial meningitis can often cause a diagnostic challenge as signs and symptoms are various and non-specific, especially in children. As delay in diagnosis and treatment of meningitis worsens its prognosis, physicians have a low threshold to perform lumbar puncture and commence antibiotics, both of which are not without risk. The evidence of this short-cut review of the literature shows that signs of meningeal irritation have variable sensitivity and specificity and therefore cannot be used alone in diagnosing meningitis.

Clinical Bottom Line

Clinical signs of meningeal irritation such as neck stiffness, Kernig's sign and Brudzinski's sign are not reliable in diagnosing bacterial meningitis particularly in neonates and infants.